"""Non-blocking, cancellable batch checks while the desktop GUI is open."""

import queue

from .runner import ProcessRunner

CHECK_INTERVAL_MS = 5 * 60 * 1000


class BatchMonitor:
    def __init__(self, scheduler, on_ready, on_status, on_output):
        self.scheduler = scheduler
        self.on_ready = on_ready
        self.on_status = on_status
        self.on_output = on_output
        self.active = False
        self.timer = None
        self.runner = None

    def start(self, command, cwd, environment, log_path):
        if self.active:
            return
        self.arguments = (command, cwd, environment, log_path)
        self.active = True
        self._check()

    def stop(self):
        self.active = False
        if self.timer is not None:
            self.scheduler.after_cancel(self.timer)
            self.timer = None
        if self.runner is not None:
            try:
                self.runner.force_stop()
            except OSError as exc:
                self.on_output(f"Arrêt de la vérification : {exc}\n")
            self.runner = None
        self.on_status("Vérification automatique arrêtée.")

    def _later(self):
        self.timer = self.scheduler.after(CHECK_INTERVAL_MS, self._check)

    def _check(self):
        self.timer = None
        if not self.active:
            return
        self.runner = ProcessRunner()
        self.on_status("Vérification des batchs en cours…")
        try:
            self.runner.start(*self.arguments)
        except (OSError, RuntimeError) as exc:
            self.on_output(f"Vérification impossible : {exc}\n")
            self.runner = None
            self.on_status("Échec de la vérification. Nouvel essai dans 5 minutes.")
            self._later()
            return
        self.timer = self.scheduler.after(100, self._poll)

    def _poll(self):
        self.timer = None
        if not self.active or self.runner is None:
            return
        while True:
            try:
                event, payload = self.runner.events.get_nowait()
            except queue.Empty:
                break
            if event in {"output", "runner_error"}:
                self.on_output(str(payload))
            elif event == "finished":
                code, interrupted = payload
                self.runner = None
                if code == 0 and not interrupted:
                    self.active = False
                    self.on_status("Tous les résultats batch sont prêts.")
                    self.on_ready()
                else:
                    self.on_status("Résultats pas encore prêts. Nouvelle vérification dans 5 minutes.")
                    self._later()
                return
        self.timer = self.scheduler.after(100, self._poll)